<template>
    <view class="u-upload" :style="[$u.addStyle(customStyle)]">
        <view class="u-upload__wrap">
            <template v-if="previewImage">
                <view class="u-upload__wrap__preview" v-for="(item, index) in lists" :key="index">
                    <image v-if="item.isImage || (item.type && item.type === 'image')" :src="item.thumb || item.url"
                        :mode="imageMode" class="u-upload__wrap__preview__image" @tap="onPreviewImage(item)" :style="[{
							width: $u.addUnit(width),
							height: $u.addUnit(height)
						}]" />
                    <view v-else class="u-upload__wrap__preview__other">
                        <u-icon color="#80CBF9" size="26"
                            :name="item.isVideo || (item.type && item.type === 'video') ? 'movie' : 'folder'"></u-icon>
                        <text
                            class="u-upload__wrap__preview__other__text">{{item.isVideo || (item.type && item.type === 'video') ? '视频' : '文件'}}</text>
                    </view>
                    <view class="u-upload__status" v-if="item.status === 'uploading' || item.status === 'failed'">
                        <view class="u-upload__status__icon">
                            <u-icon v-if="item.status === 'failed'" name="close-circle" color="#ffffff" size="30" />
                            <u-loading-icon size="22" mode="circle" color="#ffffff" v-else />
                        </view>
                        <text v-if="item.message" class="u-upload__status__message">{{ item.message }}</text>
                    </view>
                    <view class="u-upload__deletable"
                        v-if="item.status !== 'uploading' && (deletable || item.deletable)"
                        @tap.stop="deleteItem(index)">
                        <view class="u-upload__deletable__icon">
                            <u-icon name="close" color="#ffffff" size="22"></u-icon>
                        </view>
                    </view>
                    <view class="u-upload__success" v-if="item.status === 'success'">
                        <!-- #ifdef APP-NVUE -->
                        <image :src="successIcon" class="u-upload__success__icon"></image>
                        <!-- #endif -->
                        <!-- #ifndef APP-NVUE -->
                        <view class="u-upload__success__icon">
                            <u-icon name="checkmark" color="#ffffff" size="12"></u-icon>
                        </view>
                        <!-- #endif -->
                    </view>
                </view>

            </template>

            <template v-if="isInCount">
                <view v-if="$slots.default || $slots.$default" @tap="chooseFile">
                    <slot />
                </view>
                <view v-else class="u-upload__button" :hover-class="!disabled ? 'u-upload__button--hover' : ''"
                    hover-stay-time="150" @tap="chooseFile" :class="[disabled && 'u-upload__button--disabled']" :style="[{
						width: $u.addUnit(width),
						height: $u.addUnit(height)
					}]">
                    <u-icon :name="uploadIcon" size="66" :color="uploadIconColor"></u-icon>
                    <text v-if="uploadText" class="u-upload__button__text">{{ uploadText }}</text>
                </view>
            </template>
        </view>

    </view>
</template>

<script>
    import {
        chooseFile
    } from './utils';
    import mixin from './mixin.js';
    import props from './props.js';

    /**
     * upload 上传
     * @description 该组件用于上传图片场景
     * @tutorial https://uviewui.com/components/upload.html
     * @property {String}			accept				接受的文件类型, 可选值为all media image file video （默认 'image' ）
     * @property {String | Array}	capture				图片或视频拾取模式，当accept为image类型时设置capture可选额外camera可以直接调起摄像头（默认 ['album', 'camera'] ）
     * @property {Boolean}			compressed			当accept为video时生效，是否压缩视频，默认为true（默认 true ）
     * @property {String}			camera				当accept为video时生效，可选值为back或front（默认 'back' ）
     * @property {Number}			maxDuration			当accept为video时生效，拍摄视频最长拍摄时间，单位秒（默认 60 ）
     * @property {String}			uploadIcon			上传区域的图标，只能内置图标（默认 'camera-fill' ）
     * @property {String}			uploadIconColor		上传区域的图标的字体颜色，只能内置图标（默认 #D3D4D6 ）
     * @property {Boolean}			useBeforeRead		是否开启文件读取前事件（默认 false ）
     * @property {Boolean}			previewFullImage	是否显示组件自带的图片预览功能（默认 true ）
     * @property {String | Number}	maxCount			最大上传数量（默认 52 ）
     * @property {Boolean}			disabled			是否启用（默认 false ）
     * @property {String}			imageMode			预览上传的图片时的裁剪模式，和image组件mode属性一致（默认 'aspectFill' ）
     * @property {String}			name				标识符，可以在回调函数的第二项参数中获取
     * @property {Array}			sizeType			所选的图片的尺寸, 可选值为original compressed（默认 ['original', 'compressed'] ）
     * @property {Boolean}			multiple			是否开启图片多选，部分安卓机型不支持 （默认 false ）
     * @property {Boolean}			deletable			是否展示删除按钮（默认 true ）
     * @property {String | Number}	maxSize				文件大小限制，单位为byte （默认 Number.MAX_VALUE ）
     * @property {Array}			fileList			显示已上传的文件列表
     * @property {String}			uploadText			上传区域的提示文字
     * @property {String | Number}	width				内部预览图片区域和选择图片按钮的区域宽度（默认 80 ）
     * @property {String | Number}	height				内部预览图片区域和选择图片按钮的区域高度（默认 80 ）
     * @property {Object}			customStyle			组件的样式，对象形式
     * @event {Function} afterRead		读取后的处理函数
     * @event {Function} beforeRead		读取前的处理函数
     * @event {Function} oversize		文件超出大小限制
     * @event {Function} clickPreview	点击预览图片
     * @event {Function} delete 		删除图片
     * @example <u-upload :action="action" :fileList="fileList" ></u-upload>
     */
    export default {
        name: "u-upload",
        mixins: [uni.$u.mpMixin, uni.$u.mixin, mixin, props],
        data() {
            return {
                // #ifdef APP-NVUE
                successIcon: '',
                // #endif
                lists: [],
                isInCount: true,
            }
        },
        watch: {
            // 监听文件列表的变化，重新整理内部数据
            fileList: {
                immediate: true,
                handler() {
                    this.formatFileList()
                }
            },
        },
        methods: {
            formatFileList() {
                const {
                    fileList = [], maxCount
                } = this;
                const lists = fileList.map((item) =>
                    Object.assign(Object.assign({}, item), {
                        // 如果item.url为本地选择的blob文件的话，无法判断其为video还是image，此处优先通过accept做判断处理
                        isImage: this.accept === 'image' || uni.$u.test.image(item.url || item.thumb),
                        isVideo: this.accept === 'video' || uni.$u.test.video(item.url || item.thumb),
                        deletable: typeof(item.deletable) === 'boolean' ? item.deletable : this.deletable,
                    })
                );
                this.lists = lists
                this.isInCount = lists.length < maxCount
            },
            chooseFile() {
                const {
                    maxCount,
                    multiple,
                    lists,
                    disabled
                } = this;
                if (disabled) return;
                // 如果用户传入的是字符串，需要格式化成数组
                let capture;
                try {
                    capture = uni.$u.test.array(this.capture) ? this.capture : this.capture.split(',');
                } catch (e) {
                    capture = [];
                }
                chooseFile(
                        Object.assign({
                            accept: this.accept,
                            multiple: this.multiple,
                            capture: capture,
                            compressed: this.compressed,
                            maxDuration: this.maxDuration,
                            sizeType: this.sizeType,
                            camera: this.camera,
                        }, {
                            maxCount: maxCount - lists.length,
                        })
                    )
                    .then((res) => {
                        this.onBeforeRead(multiple ? res : res[0]);
                    })
                    .catch((error) => {
                        this.$emit('error', error);
                    });
            },
            // 文件读取之前
            onBeforeRead(file) {
                const {
                    beforeRead,
                    useBeforeRead,
                } = this;
                let res = true
                // beforeRead是否为一个方法
                if (uni.$u.test.func(beforeRead)) {
                    // 如果用户定义了此方法，则去执行此方法，并传入读取的文件回调
                    res = beforeRead(file, this.getDetail());
                }
                if (useBeforeRead) {
                    res = new Promise((resolve, reject) => {
                        this.$emit(
                            'beforeRead',
                            Object.assign(Object.assign({
                                file
                            }, this.getDetail()), {
                                callback: (ok) => {
                                    ok ? resolve() : reject();
                                },
                            })
                        );
                    });
                }
                if (!res) {
                    return;
                }
                if (uni.$u.test.promise(res)) {
                    res.then((data) => this.onAfterRead(data || file));
                } else {
                    this.onAfterRead(file);
                }
            },
            getDetail(index) {
                return {
                    name: this.name,
                    index: index == null ? this.fileList.length : index,
                };
            },
            onAfterRead(file) {
                const {
                    maxSize,
                    afterRead
                } = this;
                const oversize = Array.isArray(file) ?
                    file.some((item) => item.size > maxSize) :
                    file.size > maxSize;
                if (oversize) {
                    this.$emit('oversize', Object.assign({
                        file
                    }, this.getDetail()));
                    return;
                }
                if (typeof afterRead === 'function') {
                    afterRead(file, this.getDetail());
                }
                this.$emit('afterRead', Object.assign({
                    file
                }, this.getDetail()));
            },
            deleteItem(index) {
                this.$emit(
                    'delete',
                    Object.assign(Object.assign({}, this.getDetail(index)), {
                        file: this.fileList[index],
                    })
                );
            },
            // 预览图片
            onPreviewImage(item) {
                if (!item.isImage || !this.previewFullImage) return
                uni.previewImage({
                    // 先filter找出为图片的item，再返回filter结果中的图片url
                    urls: this.lists.filter((item) => this.accept === 'image' || uni.$u.test.image(item.url ||
                        item.thumb)).map((item) => item.url || item.thumb),
                    current: item.url || item.thumb,
                    fail() {
                        uni.$u.toast('预览图片失败')
                    },
                });
            },
            onPreviewVideo(event) {
                if (!this.data.previewFullImage) return;
                const {
                    index
                } = event.currentTarget.dataset;
                const {
                    lists
                } = this.data;
                wx.previewMedia({
                    sources: lists
                        .filter((item) => isVideoFile(item))
                        .map((item) =>
                            Object.assign(Object.assign({}, item), {
                                type: 'video'
                            })
                        ),
                    current: index,
                    fail() {
                        uni.$u.toast('预览视频失败')
                    },
                });
            },
            onClickPreview(event) {
                const {
                    index
                } = event.currentTarget.dataset;
                const item = this.data.lists[index];
                this.$emit(
                    'clickPreview',
                    Object.assign(Object.assign({}, item), this.getDetail(index))
                );
            }
        }
    }
</script>

<style lang="scss" scoped>
    @import '../../libs/css/components.scss';
    $u-upload-preview-border-radius: 2px !default;
    $u-upload-preview-margin: 0 8px 8px 0 !default;
    $u-upload-image-width:80px !default;
    $u-upload-image-height:$u-upload-image-width;
    $u-upload-other-bgColor: rgb(242, 242, 242) !default;
    $u-upload-other-flex:1 !default;
    $u-upload-text-font-size:11px !default;
    $u-upload-text-color:$u-tips-color !default;
    $u-upload-text-margin-top:2px !default;
    $u-upload-deletable-right:0 !default;
    $u-upload-deletable-top:0 !default;
    $u-upload-deletable-bgColor:rgb(55, 55, 55) !default;
    $u-upload-deletable-height:14px !default;
    $u-upload-deletable-width:$u-upload-deletable-height;
    $u-upload-deletable-boder-bottom-left-radius:100px !default;
    $u-upload-deletable-zIndex:3 !default;
    $u-upload-success-bottom:0 !default;
    $u-upload-success-right:0 !default;
    $u-upload-success-border-style:solid !default;
    $u-upload-success-border-top-color:transparent !default;
    $u-upload-success-border-left-color:transparent !default;
    $u-upload-success-border-bottom-color: $u-success !default;
    $u-upload-success-border-right-color:$u-upload-success-border-bottom-color;
    $u-upload-success-border-width:9px !default;
    $u-upload-icon-top:0px !default;
    $u-upload-icon-right:0px !default;
    $u-upload-icon-h5-top:1px !default;
    $u-upload-icon-h5-right:0 !default;
    $u-upload-icon-width:16px !default;
    $u-upload-icon-height:$u-upload-icon-width;
    $u-upload-success-icon-bottom:-10px !default;
    $u-upload-success-icon-right:-10px !default;
    $u-upload-status-right:0 !default;
    $u-upload-status-left:0 !default;
    $u-upload-status-bottom:0 !default;
    $u-upload-status-top:0 !default;
    $u-upload-status-bgColor:rgba(0, 0, 0, 0.5) !default;
    $u-upload-status-icon-Zindex:1 !default;
    $u-upload-message-font-size:12px !default;
    $u-upload-message-color:#FFFFFF !default;
    $u-upload-message-margin-top:5px !default;
    $u-upload-button-width:80px !default;
    $u-upload-button-height:$u-upload-button-width;
    $u-upload-button-bgColor:rgb(244, 245, 247) !default;
    $u-upload-button-border-radius:2px !default;
    $u-upload-botton-margin: 0 8px 8px 0 !default;
    $u-upload-text-font-size:11px !default;
    $u-upload-text-color:$u-tips-color !default;
    $u-upload-text-margin-top: 2px !default;
    $u-upload-hover-bgColor:rgb(230, 231, 233) !default;
    $u-upload-disabled-opacity:.5 !default;

    .u-upload {
        @include flex(column);
        flex: 1;

        &__wrap {
            @include flex;
            flex-wrap: wrap;
            flex: 1;

            &__preview {
                border-radius: $u-upload-preview-border-radius;
                margin: $u-upload-preview-margin;
                position: relative;
                overflow: hidden;
                @include flex;

                &__image {
                    width: $u-upload-image-width;
                    height: $u-upload-image-height;
                }

                &__other {
                    width: $u-upload-image-width;
                    height: $u-upload-image-height;
                    background-color: $u-upload-other-bgColor;
                    flex: $u-upload-other-flex;
                    @include flex(column);
                    justify-content: center;
                    align-items: center;

                    &__text {
                        font-size: $u-upload-text-font-size;
                        color: $u-upload-text-color;
                        margin-top: $u-upload-text-margin-top;
                    }
                }
            }
        }

        &__deletable {
            position: absolute;
            top: $u-upload-deletable-top;
            right: $u-upload-deletable-right;
            background-color: $u-upload-deletable-bgColor;
            height: $u-upload-deletable-height;
            width: $u-upload-deletable-width;
            @include flex;
            border-bottom-left-radius: $u-upload-deletable-boder-bottom-left-radius;
            align-items: center;
            justify-content: center;
            z-index: $u-upload-deletable-zIndex;

            &__icon {
                position: absolute;
                transform: scale(0.7);
                top: $u-upload-icon-top;
                right: $u-upload-icon-right;
                /* #ifdef H5 */
                top: $u-upload-icon-h5-top;
                right: $u-upload-icon-h5-right;
                /* #endif */
            }
        }

        &__success {
            position: absolute;
            bottom: $u-upload-success-bottom;
            right: $u-upload-success-right;
            @include flex;
            // 由于weex(nvue)为阿里巴巴的KPI(部门业绩考核)的laji产物，不支持css绘制三角形
            // 所以在nvue下使用图片，非nvue下使用css实现
            /* #ifndef APP-NVUE */
            border-style: $u-upload-success-border-style;
            border-top-color: $u-upload-success-border-top-color;
            border-left-color: $u-upload-success-border-left-color;
            border-bottom-color: $u-upload-success-border-bottom-color;
            border-right-color: $u-upload-success-border-right-color;
            border-width: $u-upload-success-border-width;
            align-items: center;
            justify-content: center;
            /* #endif */

            &__icon {
                /* #ifndef APP-NVUE */
                position: absolute;
                transform: scale(0.7);
                bottom: $u-upload-success-icon-bottom;
                right: $u-upload-success-icon-right;
                /* #endif */
                /* #ifdef APP-NVUE */
                width: $u-upload-icon-width;
                height: $u-upload-icon-height;
                /* #endif */
            }
        }

        &__status {
            position: absolute;
            top: $u-upload-status-top;
            bottom: $u-upload-status-bottom;
            left: $u-upload-status-left;
            right: $u-upload-status-right;
            background-color: $u-upload-status-bgColor;
            @include flex(column);
            align-items: center;
            justify-content: center;

            &__icon {
                position: relative;
                z-index: $u-upload-status-icon-Zindex;
            }

            &__message {
                font-size: $u-upload-message-font-size;
                color: $u-upload-message-color;
                margin-top: $u-upload-message-margin-top;
            }
        }

        &__button {
            @include flex(column);
            align-items: center;
            justify-content: center;
            width: $u-upload-button-width;
            height: $u-upload-button-height;
            background-color: $u-upload-button-bgColor;
            border-radius: $u-upload-button-border-radius;
            margin: $u-upload-botton-margin;
            /* #ifndef APP-NVUE */
            box-sizing: border-box;
            /* #endif */

            &__text {
                font-size: $u-upload-text-font-size;
                color: $u-upload-text-color;
                margin-top: $u-upload-text-margin-top;
            }

            &--hover {
                background-color: $u-upload-hover-bgColor;
            }

            &--disabled {
                opacity: $u-upload-disabled-opacity;
            }
        }
    }
</style>
